Asymptomatic intraspinal epidermoid cyst in a 7-year-old male with juvenile idiopathic arthritis identified by an advanced physiotherapist practitioner: a case report.

BACKGROUND Pediatric intraspinal epidermoid cysts are rare with potential to cause life-altering outcomes if not addressed. Reports to date describe symptomatic presentations including loss of bladder or bowel function and motor and sensory losses. This case report identifies the diagnostic challenge of an asymptomatic intraspinal epidermoid cyst in the cauda equina region presenting in a 7-year-old male with juvenile idiopathic arthritis (JIA). DIAGNOSIS An advanced physiotherapist practitioner assessed and diagnosed a previously healthy 7-year-old-male of South Asian descent with JIA based on persistent knee joint effusions. Complicating factors delayed the investigation of abnormal functional movement patterns, spinal and hip rigidity and severe restriction of straight leg raise, all atypical for JIA. Further delaying the diagnosis was the lack of subjective complaints including no pain, no reported functional deficits, and no neurologic symptoms. A spinal MRI investigation 10-months from initial appointment identified intraspinal epidermoid cysts occupying the cauda equina region requiring urgent referral to neurosurgery. DISCUSSION Clinical characteristics and pattern recognition are essential for diagnosing spinal conditions in pediatric populations. Diagnostic challenges present in this case included co-morbidity (JIA), a severe adverse reaction to treatment, a lack of subjective complaints and a very low prevalence of intraspinal epidermoid cysts. IMPACT STATEMENTS Early signs of pediatric asymptomatic intraspinal epidermoid cysts included abnormal functional movement patterns, rigidity of spine, severely limited straight leg raise and hip flexion without pain. Advanced physiotherapist practitioners can be integral to pediatric rheumatology teams considering their basic knowledge in musculoskeletal examination and functional mobility assessment when identifying rare spinal conditions that present within the complex context of rheumatic diseases.